Stability and Memory Pressure in 8.2

[Jim Gettys]

On Tue, 2008-09-09 at 13:10 -0400, Daniel Drake wrote:
> On Tue, 2008-09-09 at 00:10 -0400, Michael Stone wrote:
> >     - whether we can get Browse to behave intelligently when it receives
> >       BadAlloc errors from X?
> 
> I have no doubt that Browse/xulrunner has room for improvement with
> memory usage but this is not where you should be looking. These BadAlloc
> messages are true errors generated when the application requests pixmaps
> outside of the coordinate range accepted by X (this is well
> documented). 
> 
> This is a real bug in the code, not a memory pressure issue. Such
> requests should never be generated, and the application crashing is
> probably the behaviour we want.

For the specific BadAlloc of the page in our wiki, it is not coordinate
out of range, but that the images on that page are so huge as to cause X
to get a allocation failure from the OS, and that gets reflected back to
the client.  Otherwise we'd have gotten a BadValue error.  At one point,
X11 was pretty carefully checked to work in the face of failures to
allocate memory (dunno how true that is today).

Whether Firefox should be so silly as to even be asking (the images are
huge) and asking the X server to rescale them (also very questionable)
is something that can/should be taken up with the Firefox folks, but not
something we're going to (be able) to fix on our own.  The embedded
mozilla folks (there are such people at long last) are the logical
people to own this headache.
                               - Jim

-- 
Jim Gettys <jg at laptop.org>
One Laptop Per Child